Field of the Invention
The present invention relates to an abnormality analysis system and an analysis apparatus used in an abnormality analysis system.
Description of Related Art
In Patent Literature 1, a method for monitoring a grinding burn of a workpiece is described. In the method, during grinding of a workpiece, by detecting a grinding load of a grinding wheel and a rotation speed of the workpiece and comparing the detected grinding load with a threshold of the grinding load according to the rotation speed, the presence/absence of the occurrence of a grinding burn is determined. Here, the threshold is set based on the grinding load of the grinding wheel with respect to the rotation speed of the workpiece at the time of the occurrence of a grinding burn of the workpiece.
In Patent Literature 2, it is described that trial grinding is performed, and a threshold is set based on a grinding load acquired in the trial grinding. Thereafter, by comparing a grinding load detected in actual grinding with the threshold, the presence/absence of the occurrence of a grinding abnormality is determined.
In Patent Literature 3, it is described to predict a quality abnormality of a product based on a quality tendency pattern as below. For example, in a case where the outer peripheral faces of workpiece are grinded using a grinding wheel, as the number of the workpieces increases, the dimension precision tends to deteriorate (see FIG. 4 of Patent Literature 3). In addition, based on a relation between a grinding time and grinding resistance of one workpiece, a relation between the number of workpieces and an average value of the grinding resistance is acquired (see FIGS. 5 and 10 of Patent Literature 3). Then, by considering a relation between the number of workpieces and the dimension precision, in a quality tendency pattern representing a relation between the number of workpieces and an average value of grinding resistance, a threshold for the average value of the grinding resistance can be set. In other words, by acquiring grinding resistance and the number of workpieces, an abnormality of a product can be predicted based on the quality tendency pattern and the threshold.